840 crashes same location every time

Wat happens when you make another (different) route with that location? Sounds like a fault in the route?

I experienced it spuriously when passing high voltage equipment as a railway crossing - no crash, but a loss of gps-signal.

It's not a planned/mapped route on the garmin, just the say path I take , if that makes sense.  And only started happenign recently.

if you turn off the climbpro and ride on this same route, is the problem exist or not at the same location? 

Garmin - AL 

That might (or might not) stop that particular crash but it still doesn't fix the underlying bug. The Edge mapping engine shouldn't crash whatever the GPS data and testing for this by deliberately feeding it garbage should be a key test in quality control (and cyber security).